High-Pressure Cleaning Device

ABSTRACT

A high-pressure cleaning device has a conveying pump and a conveying conduit with a spray opening. The conveying conduit conveys cleaning liquid, conveyed by the conveying pump, in a conveying direction from the conveying pump to the spray opening of the conveying conduit. A switch element is provided that has at least a first switched state and a second switched state. An actuator is provided that adjusts the switch element between the first switched state and the second switched state. The high-pressure cleaning device is provided such that the actuator adjusts the switch element between the first switched state and the second switched state by an adjusting force effected by the cleaning liquid on the actuator.

BACKGROUND OF THE INVENTION

The invention relates to a high-pressure cleaning device comprising aconveying pump, a conveying conduit through which by means of theconveying pump cleaning liquid can be conveyed in a conveying directionfrom the conveying pump to a spray opening of the conveying conduit, aswitch element comprising at least a first switched state and a secondswitched state, and an actuator for adjusting the switch element betweenthe first and the second switched states.

WO 2012/095238 discloses a high-pressure cleaning device with a manuallyrotatable switch element. By rotation of the switch element, variousnozzles can be selected for operation of the high-pressure cleaningdevice. For this purpose, the lance of the high-pressure cleaning devicemust be held with both hands and the switch element must be rotatedrelative to a base member of the lance.

It is an object of the invention to further develop a high-pressurecleaning device of the aforementioned kind such that a simple andcomfortable adjustment of the switch element is possible.

SUMMARY OF THE INVENTION

In accordance with the invention, this object is solved in that thehigh-pressure cleaning device is configured such that the actuator, dueto a force effected by the cleaning liquid on the actuator, can adjustthe switch element between the first switched state and the secondswitched state.

In this way, the switch element can be comfortably adjusted. A user ofthe high-pressure cleaning device must not himself exert a force to dothis. The switch element can be automatically switched by utilizing thepressure of the cleaning liquid. Since the pressure of the cleaningliquid or the cleaning liquid itself is utilized for adjusting theswitch element, a simple configuration of the high-pressure cleaningdevice results. No additional motors or pressure circuits are required.

Advantageously, the high-pressure cleaning device comprises at least afirst work element and a second work element. Expediently, in the firstswitched state of the switch element, the first work element is switchedand connected to the conveying conduit; in the second switched state ofthe switch element, the second work element is switched and connected tothe conveying conduit. By adjustment of the switch element, various workelements can thus be switched and connected to the conveying conduit ina simple manner.

In particular, the first work element and the second work element arenozzles. In this way, a comfortable nozzle exchange can be enabled.Depending on the selection of the individual nozzles, a pressureadjustment or pressure change without change of the volume flow in theconveying conduit is possible in this way. Even in case of a pressurereduction, operation with the full flow rate can be realized.

Expediently, the high-pressure cleaning device comprises a conveyanceactuating element with which the passage of cleaning liquid through theconveying conduit in an open position of the conveyance actuatingelement is permitted and is blocked in a closed position of theconveyance actuating element. The conveyance actuating element isarranged between the conveying pump and the spray opening in theconveying conduit.

In an advantageous embodiment of the invention, the high-pressurecleaning device comprises a branch conduit that connects the conveyingconduit at a branch location of the conveying conduit to the actuator.In this way, cleaning liquid can be conveyed to the actuator in a simplemanner.

Expediently, between the branch location and the actuator a switchactuating element is provided with which the passage of cleaning liquidthrough the branch conduit in a passage position of the switch actuatingelement is permitted and in a blocking position of the switch actuatingelement is prevented. As a function of the position of the switchactuating element, the actuator can be loaded, or not loaded, withpressure of the cleaning liquid. The switch actuating element dividesthe branch conduit into a holding section, extending from the branchlocation to the switch actuating element, and into a pressure section,extending from the switch actuating element to the actuator.

In particular, the high-pressure cleaning device is configured suchthat, in operation of the high-pressure cleaning device, a holdingpressure is present in the holding section of the branch conduit whenthe switch actuating element is in the blocking position and theconveyance actuating element is in the closed position. Expediently, thehigh-pressure cleaning device is configured such that the holdingpressure can be increased by the conveying pump when the switchactuating element is in the blocking position and the conveyanceactuating element is in the closed position. In particular, the holdingpressure can be so high that it is at least high enough in order toexert on the actuator the adjusting force for adjusting the switchelement. In this way, the pressure of the cleaning liquid can beutilized in a simple manner for adjustment of the switch element.

Advantageously, the branch location of the conveying conduit is arrangedbetween the conveying pump and the conveyance actuating element in theconveying conduit. In this way, the conveyance actuating element can beclosed and then, by means of the conveying pump, a sufficiently highholding pressure can be built up. Expediently, the conveyance actuatingelement is arranged between the conveying pump and the switch elementarranged in the conveying conduit. In this way, the high-pressurecleaning device can be configured such that the switch element in theclosed position of the conveyance actuating element is no longer loadedwith pressure by the conveying pump and the cleaning liquid. Anadjustment of the switch element between the first switched state andthe second switched state is then possible in a simple manner.

In an advantageous further embodiment of the invention, between thebranch location of the conveying conduit and the conveying pump aconveyance check valve is arranged in the conveying conduit. Theconveyance check valve prevents a flow of cleaning liquid opposite tothe conveying direction. In this way, a sufficiently large holdingpressure can be built up in the branch conduit.

In an advantageous further embodiment of the invention, thehigh-pressure cleaning device is configured such that in operation ofthe high-pressure cleaning device, when in the holding section of thebranch conduit a sufficient holding pressure is present, the cleaningliquid advances from the holding section into the pressure section ofthe branch conduit upon adjustment of the switch actuating element fromthe blocking position into the passage position and exerts on theactuator the adjusting force for adjustment of the switch elementbetween the first switched state and the second switched state. In thismanner, a different nozzle can be switched and connected to theconveying conduit, for example.

In an advantageous embodiment of the invention, the high-pressurecleaning device comprises a drainage return channel. Expediently, thedrainage return channel connects the pressure section of the branchconduit with an element section of the conveying conduit extending fromthe conveyance actuating element to the spray opening. In particular,the high-pressure cleaning device is configured such that the drainagereturn channel is interrupted in the passage position of the switchactuating element; in the blocking position of the switch actuatingelement, a flow of cleaning liquid is possible only in the directionfrom the pressure section to the element section. In this way, apressure reduction in the pressure section of the branch conduit ispossible. In this context, cleaning liquid flows from the pressuresection to the element section of the conveying conduit. As a result ofthis, the pressure acting on the actuator decreases.

Expediently, the high-pressure cleaning device is configured such that adrainage check valve in the blocking position of the switch actuatingelement is switched and connected to the drainage return channel. Inparticular, the drainage check valve is a component of the switchactuating element. Advantageously, in the passage position of the switchactuating element, the drainage check valve is removed from the drainagereturn channel due to the adjustment of the switch actuating element. Inthis way, the arrangement of the drainage check valve in the drainagereturn channel is coupled in a simple way to the position of the switchactuating element.

Advantageously, the switch actuating element is in operative connectionwith a first restoring spring in such a way that it is loaded with aforce in the direction toward its blocking position. In this way, it isensured that the switch actuating element, when not actuated by a user,returns into the blocking position.

In particular, the conveyance actuating element is in operativeconnection with a second restoring spring in such a way that it isloaded by a force in the direction of its closed position.

Expediently, the actuator comprises a rest position and an adjustedposition wherein the actuator must be moved for adjustment of the switchelement from the rest position into the adjusted position. Inparticular, the actuator is in operative connection with a thirdrestoring spring in such a way that it is loaded by a force in thedirection toward the rest position.

Advantageously, the actuator is guided in a cylinder of a hydrauliccylinder. In this way, the actuator can be produced in a simple manner.

In an advantageous further embodiment of the invention, thehigh-pressure cleaning device is configured such that the actuator canadjust the switch element due to a force exerted by the operator of thehigh-pressure cleaning device on the actuator.

BRIEF DESCRIPTION OF THE DRAWING

An embodiment of the invention will be explained in the following withthe aid of the drawing.

FIG. 1 is a schematic illustration of a diagram of connections of ahigh-pressure cleaning device.

FIG. 2 is a schematic, partially sectioned illustration of ahigh-pressure gun of the high-pressure cleaning device according to FIG.1.

FIG. 3 is a schematic illustration of the diagram of connections of FIG.1, wherein a conveyance actuating element is in an open position, aswitch actuating element in a blocking position, and an actuator in arest position.

FIG. 4 is a schematic illustration of the diagram of connections of FIG.1, wherein the conveyance actuating element is in a closed position, theswitch actuating element in the blocking position, and the actuator inthe rest position.

FIG. 5 is a schematic illustration of the diagram of connections of FIG.1, wherein the conveyance actuating element is in the closed position,the switch actuating element in the passage position, and the actuatorin an adjusted position.

FIG. 6 is a schematic illustration of the diagram of connections of toFIG. 1, wherein the conveyance actuating element is in the closedposition, the switch actuating element in the blocked position, and theactuator in the adjusted position, wherein a drainage return channel isopen.

FIG. 7 is a schematic illustration of the diagram of connections of FIG.1, wherein the conveyance actuating element is in the closed position,the switch actuating element in the blocking position, and the actuatorin the rest position, wherein a drainage return channel is open.

FIG. 8 is a schematic illustration of the diagram of connections of FIG.1, wherein the conveyance actuating element is in the open position, theswitch actuating element in the blocked position, and the actuator inthe rest position.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows a schematic illustration of a diagram of connections of ahigh-pressure cleaning device 1. The high-pressure cleaning device 1comprises a conveying conduit 10. The conveying conduit 10 connects aconveying pump 2 with a spray opening 19. The conveying pump 2 conveyscleaning liquid from the conveying pump 2 through the conveying conduit10 to the spray opening 19. The conveying pump 2 conveys cleaning liquidfrom a liquid container 36 through a filter 37 to the spray opening 19.The spray opening 19 is the end of the conveying conduit 10. Thecleaning liquid exits under high pressure from the spray opening 19. Theconveying pump 2 conveys cleaning liquid in a conveying direction 50 inthe conveying conduit 10.

The high-pressure cleaning device 1 comprises a conveyance actuatingelement 11. The conveyance actuating element 11 is arranged between theconveying pump 2 and the spray opening 19. By means of the conveyanceactuating element 11, passage of cleaning liquid through the conveyingconduit 10 can be permitted or prevented. In an open position 12(FIG. 1) of the conveyance actuating element 11, conveyance of cleaningliquid from the conveying pump 2 to the spray opening 19 is possible. Ina closed position 13 (FIG. 4) of the conveyance actuating element 11,conveyance of cleaning liquid from the conveying pump 2 to the sprayopening 19 is prevented. The high-pressure cleaning device 1 comprises asecond restoring spring 17. The conveyance actuating element 11 is inoperative connection with the second restoring spring 17 such that it isloaded by a force in the direction toward its closed position 13. Onlywhen the conveyance actuating element 11 is held in the open position12, the cleaning liquid can pass through the conveyance actuatingelement 11. When the conveyance actuating element 11 is not held in theopen position 12, it is returned due to the force load by the secondrestoring spring 17 into its closed position 13. The conveyanceactuating element 11 is configured as a switch which can be actuated byhand by a user.

As is illustrated in FIG. 2, the high-pressure cleaning device 1comprises a high-pressure gun 44. The high-pressure gun 44 comprises agrip 42 and a lance 43. The conveyance actuating element 11 is arrangedat the grip 42. The lance 43 extends in a longitudinal direction 49. Thehigh-pressure gun 44 comprises in longitudinal direction 49 alongitudinal end 45. The longitudinal end 45 is facing away from thespray opening 19. At one end of the high-pressure gun 44, the sprayopening 19 is arranged and at the other end the longitudinal end 45 isarranged. The high-pressure gun 44 comprises a longitudinal section 46.The longitudinal section 46 begins at the longitudinal end 45 andextends in longitudinal direction 49. The high-pressure gun 44 comprisesa length d measured in longitudinal direction 49. The longitudinalsection 46 extends across one fourth of the length d of thehigh-pressure gun 44. The conveyance actuating element 11 is arranged inthe longitudinal section 46.

As illustrated in FIGS. 1 and 2, the high-pressure cleaning device 1comprises a switch element 3. The switch element 3 comprises at least afirst switched state and a second switched state. In the embodiment, thehigh-pressure cleaning device 1 comprises a first work element 4 and asecond work element 5. In the first switched state, the first workelement 4 is switched and connected to the conveying conduit 10 (FIGS.1, 3 and 4); in the second switched state, the second work element 5 isswitched and connected to the conveying conduit 10 (FIGS. 5 through 8).In the embodiment, in the first switched state only the first workelement 4 is switched and connected to the conveying conduit 10; in thesecond switched state, only the second work element 5 is switched andconnected to the conveying conduit 10. The first work element 4 and thesecond work element 5 are nozzles. However, it can also be provided thatthe switch element is a simple switch and no work elements are providedthat are switched and connected to the conveying conduit.

In the embodiment according to FIGS. 1 through 8, a plurality ofswitched states are provided. In a third switched state, a third nozzle47 is switched and connected to the conveying conduit 10. In theembodiment according to FIGS. 1 through 8, the high-pressure cleaningdevice 1 comprises at least three work elements 4, 5, and 47 embodied asnozzles.

As illustrated in FIG. 2, the conveying conduit 10 branches in theregion between the switch element 3 and the spray opening 19. A firstbranch 33 opens at the spray opening 19 into the first work element 4embodied as a nozzle. A second branch 34 opens at the spray opening 19into the second work element 5 embodied as a nozzle. The number ofbranches corresponds to the number of switched states of the switchelement 3. The high-pressure cleaning device 1 comprises a third nozzle47 (FIG. 1). The branches 33 and 34 are arranged in a base member 29 ofthe lance 43 of the high-pressure cleaning device 1. The branches 33 and34 are channels in the base m ember 29.

The switch element 3 is rotatably supported about an axis of rotation 48(FIG. 2). The axis of rotation 48 extends in the longitudinal direction49. The switch element 3 comprises a switch channel 27. The switchchannel 27 comprises a mouth 28. The mouth 28 is facing the sprayopening 19. The mouth 28 is arranged eccentrically in relation to theaxis of rotation 48. The mouth 28 is arranged at a distance from theaxis of rotation 48. In a first switched state of the switch element 3,the switch channel 29 opens with the mouth 28 into the first branch 33of the branch conduit 20. In the second switched state of the switchelement 3 illustrated in FIG. 2, the switch channel 27 opens with itsmouth 28 into the second branch 34 of the branch conduit 20. In thefirst switch state and in the second switch state, the switch element 3is pushed in the direction toward the spray opening 19 against the basemember 29. For this purpose, a spring (not illustrated) is provided.Between the switch element 3 and the base member 29, a sealing ring, notillustrated, is arranged. Since the switch element 3 is pressed againstthe base member 29, the connection between the switch channel 27 and thebranches 33, 34 is sufficiently sealed for passing the cleaning liquidtherethrough.

When switching the switch element 3 from the first switched state intothe second switched state, the switch element 3 is rotated about theaxis of rotation 48 illustrated in FIG. 2. When switching from the firstswitched state into the second switched state, the switch element 3 isfirst moved, prior to a rotation about the axis of rotation 48, in thedirection opposite to the longitudinal direction 49 away from the sprayopening 19. This is possible because no pressure is exerted by thecleaning liquid on the switch element 3 when the conveyance actuatingelement 11 is in the closed position 13. The high-pressure cleaningdevice 1 is configured such that the switch element 3 in the closedposition 13 of the conveyance actuating element 11 is movable in thedirection away from the spray opening 19 relative to the base member 29.In this way, wear of the sealing ring and of the high-pressure cleaningdevice 1 when switching the switch element can be minimized. Uponswitching by a rotational movement of the switch element 3 in relationto the base member 29, the sealing ring is thus not as strongly, or notat all, pressed against the base member 29. Therefore, no frictionforces, or hardly any friction forces, are acting between the sealingring and the base member 29 during switching. The high-pressure cleaningdevice is configured such that the switch element 3, after adjustment ofthe switch element 3 between the first switched state and the secondswitched state, is pressed again in the direction toward the sprayopening 19 against the base member 29.

The first branch 33 extends to the first work element 4. The secondbranch 34 extends to the second work element 5. By rotation of theswitch element 3 about the axis of rotation 48, various work elements 4,5 can be switched and connected to the conveying conduit 10. The firstbranch 33 in the first switched state of the switch element 3 is acomponent of the conveying conduit 10. In the first switched state ofthe switch element 3, the second branch 34 is not a component of theconveying conduit 10. In the second switched state of the switch element3, this second branch 34 is a component of the conveying conduit 10 andthe first branch 33 is not a component of the conveying conduit 10. Theswitch element 3 in the embodiment is also referred to as a nozzleswitch. The switch element 3 is arranged in the conveying conduit 10.

It can also be provided that the work elements are components of theswitch element. In this case, the work elements are moved together withthe switch element. Then, the work elements can be moved together withthe switch element and thus switched and connected to the conveyingconduit.

In the embodiment, the high-pressure cleaning device 1 comprises anactuator 6. The actuator 6 serves for adjusting the switch element 3between the first switched state and the second switched state. Thehigh-pressure cleaning device 1 is designed such that the actuator 6,due to an adjusting force effected by the cleaning liquid on theactuator 6, can adjust the switch element 3 between the first switchedstate and the second switched state. In the embodiment according toFIGS. 1 through 8, the pressure of the cleaning liquid effects anadjustment of the switch element 3 between the first switched state andthe second switched state. For adjusting the switch element 3, theactuator 6 is acting on the switch element 3. In the embodiment, theactuator 6 is guided in a cylinder 41 of a hydraulic cylinder 40. Theactuator 6 comprises the piston and the piston rod of the hydrauliccylinder 40. The actuator 6 is a component of the hydraulic cylinder 40.The actuator 6 can move back and forth in the hydraulic cylinder 40between a rest position 7 (FIG. 1) and an adjusted position 8 (FIG. 5).The actuator 6 is in operative connection with a third restoring spring9 in such a way that it is loaded by a force in the direction toward therest position 7. The third restoring spring 9 is arranged between thepiston of the actuator 6 and the cylinder 41.

For adjusting the switch element 3, the actuator 6 must be moved fromthe rest position 7 into the adjusted position 8. The piston of theactuator 6 delimits with a portion of the cylinder 41 of the hydrauliccylinder 40 a pressure chamber 32. The volume of the pressure chamber 32is minimal in the rest position 7 of the actuator 6. The pressurechamber 32 is connected by a branch conduit 20 to the conveying conduit10. The conveying conduit 10 comprises a branch location 14. The branchconduit 20 connects the branch location 14 with the actuator 6. Thebranch conduit 20 connects the pressure chamber 32 in fluidcommunication with the conveying conduit 10. The actuator 6 is arrangedat the end of the branch conduit 20. The branch location 14 is arrangedbetween the conveying pump 2 and the conveyance actuating element 11 inthe conveying conduit 10.

A switch actuating element 21 is provided between the branch location 14and the actuator 6. With the switch actuating element 21, a passagethrough the branch conduit 20 can be opened or closed. By means of theswitch actuating element 21, passage of cleaning liquid through thebranch conduit 20 is permitted in the passage position 22 (FIG. 5) ofthe switch actuating element 21; in a blocking position 23 (FIG. 1, FIG.3, FIG. 4, FIGS. 6 to 8) of the switch actuating element 21, passage ofcleaning liquid is prevented. In the passage position 22 of the switchactuating element 21, the cleaning liquid can pass the passageway at theswitch actuating element 21. In the blocking position 23, the cleaningliquid cannot flow through the passageway. The high-pressure cleaningdevice 1 comprises a first restoring spring 26. The switch actuatingelement 21 is in operative connection with the first restoring spring 26in such a way that it is loaded by a force in the direction toward itsblocking position 23. When the switch actuating element 21 is not heldin the passage position 22, it is returned due to the force of the firstrestoring spring 26 into its blocking position 23.

The switch actuating element 21 is arranged between the branch location14 and the actuator 6 in the branch conduit 20. As illustrated in FIG.2, the switch actuating element 21 is arranged in the longitudinalsection 46 of the high-pressure gun 44. When the grip is gripped by ahand of the user, the switch actuating element 21 can be operated withthe same hand with which the grip 42 is gripped. The switch actuatingelement 21 divides the branch conduit 20 into a holding section,extending from the branch location 14 to the switch actuating element21, and into a pressure section 25 (FIG. 1), extending from the switchactuating element 21 to the actuator 6. The pressure section 25 extendsbetween the switch actuating element 21 and the pressure chamber 32. Theholding section 24 extends between the branch location 14 and the switchactuating element 21.

In the branch conduit 20, a throttle element 38 is arranged. Thethrottle element 38 is arranged in the pressure section 25 of the branchconduit 20. In this way, the flow rate of the cleaning liquid along itspath to the actuator 6 can be regulated. In particular, the flow ratecan be increased in this way.

The high-pressure cleaning device 1 comprises a drainage return channel30. The conveying conduit 10 comprises an element section 16 and a pumpsection 18. The pump section 18 extends between the conveying pump 2 andthe conveyance actuating element 11. The element section 16 extendsbetween the conveyance actuating element 11 and the spray opening 19.The drainage return channel 30 connects the pressure section 25 of thebranch conduit 20 with the element section 16 of the conveying conduit10. The drainage return channel 30 opens at a drainage location 35 ofthe conveying conduit 10 into the conveying conduit 10. The drainagelocation 35 is arranged between the conveyance actuating element 11 andthe switch element 3 in the conveying conduit 10. The high-pressurecleaning device 1 comprises a drainage check valve 31. In the blockingposition 23 of the switch actuating element 21, the drainage check valve31 is arranged in the drainage return channel 30. Then, the drainagecheck valve 31 enables flow of cleaning liquid from the pressure section25 of the branch conduit 20 into the element section 16 of the conveyingconduit 10. The drainage check valve 31 prevents flow of cleaning liquidin the direction from the drainage location 35 to the pressure section25 through the drainage return channel 30.

The high-pressure cleaning device 1 comprises a conveyance check valve15. The conveyance check valve 15 is arranged in the pump section 18 ofthe conveying conduit 10. The conveyance check valve 15 is arrangedbetween the conveying pump 2 and the conveyance actuating element 11 inthe conveying conduit 10. The conveyance check valve 15 is arrangedbetween the branch location 14 and the conveying pump 2. The conveyancecheck valve 15 prevents a flow of cleaning liquid opposite to theconveying direction 50. The conveyance check valve 15 enables a flow ofcleaning liquid in the conveying direction 50.

FIGS. 3 to 8 show the high-pressure cleaning device 1 in variousoperating states. In the schematic diagram of connections, cleaningliquid which is under high pressure is illustrated by thick solid lines.Cleaning liquid that is at low pressure is illustrated by dotted lines.In FIG. 3, the conveyance actuating element 11 is in the open position12. The switch actuating element 21 is in the blocking position 23. Theconveying pump 2 conveys cleaning liquid from the liquid container 36through the conveying conduit 10 to the spray opening 19. Cleaningliquid is sprayed from the spray opening 19 at high pressure. Thecleaning liquid in the conveying conduit 10 is under high pressure. Thecleaning liquid in the holding section 24 of the branch conduit 20 isunder high pressure. The cleaning liquid in the section of the drainagereturn channel 30 between the switch actuating element 21 and thedrainage location 35 is under high pressure. In the pressure section 25of the branch conduit 20, there is no or only little cleaning liquid.This cleaning liquid is not pressurized or only minimally pressurized.The switch element 3 is in the first switched state. In the firstswitched state of the switch element 3, the switch element 3 guides thecleaning liquid to the first work element 4. The first work element 4 isswitched and connected to the conveying conduit 10. The actuator 6 is inthe rest position 7.

In FIG. 4, the conveyance actuating element 11 is no longer held in theopen position 12. The second restoring spring 17 has pushed theconveyance actuating element 11 into the closed position 13. Theconveyance actuating element 11 is in the closed position 13. The switchactuating element 21 is still in the blocking position 23. No cleaningliquid sprays from the spray opening 19. The cleaning liquid in the pumpsection 18 and in the holding section 24 is under high pressure. Thehigh-pressure cleaning device 1 is configured such that, in operation ofthe high-pressure cleaning device 1, a holding pressure is present inthe holding section 24 of the branch line 20 in the blocking position 23of the switch actuating element 21, while the conveyance actuatingelement 11 is in the closed position 13. In the state illustrated inFIG. 4, the holding pressure corresponds to the high pressure of thehigh-pressure cleaning device 1. The high-pressure cleaning device 1 isconfigured such that the holding pressure can be increased by means ofthe conveying pump in the blocking position 23 of the switch actuatingelement 21, while the conveyance actuating element 11 is in the closedposition 13.

This can be required, for example, when the holding pressure has droppeddue to multiple actuations of the actuator 6 by actuation of the switchactuating element 21. At the point in time illustrated in FIG. 4, theswitch actuating element 21 is in its blocking position 23 and nopressure is acting on the actuator 6. The actuator 6 is in its restposition 7. The switch element 3 is still in its first switched state.The switch channel 27 of the switch element 3 illustrated in FIG. 2leads to the first branch 33 of the conveying conduit 10 and to thefirst work element 4 (this situation is not illustrated in FIG. 2). Thepressure of the cleaning liquid existing in the holding section 24 inregard to its absolute value is at least high enough that it can exertthe force for adjusting the switch element 3 on the actuator 6. This ishowever done only once the switch actuating element 21 has been movedfrom the blocking position 23 into the passage position 22.

This is illustrated in FIG. 5. FIG. 5 shows the high-pressure cleaningdevice 1 with the conveyance actuating element 11 in the closed position13 and the switch actuating element 21 in the passage position 22. Thehigh-pressure cleaning device 1 is configured such that in operation ofthe high-pressure cleaning device 1, when a sufficient holding pressureis existing in the holding section 24 of the branch line 20, thecleaning liquid advances from the holding section 24 into the pressuresection 25 of the branch line 20 upon switching of the switch actuatingelement 21 from the blocking position 23 (FIG. 4) into the passageposition 25 (FIG. 5) and exerts on the actuator 6 the force foradjusting the switch element 3.

In the embodiment according to FIGS. 1 through 8, this causes adifferent work element 4, 5, 47 to be switched and connected to theconveying conduit 10. As illustrated in FIG. 5, a force is acting on theswitch element 3 by means of the actuator 6 and this force has theeffect that, instead of the first work element 4, the second workelement 5 is switched and connected to the conveying conduit 10. Forthis purpose, the actuator 6 is moved from its rest position 7 into itsadjusted position 8. This is done by means of the force of the cleaningliquid. The holding pressure of the cleaning liquid is now also actingon the actuator 6 and pushes the actuator 6 in the direction toward itsadjusted position 8. In this context, the volume of the pressure chamber32 of the hydraulic cylinder 40 is enlarged. In the embodiment accordingto FIGS. 1 through 8, the adjustment of the switch element 3 is realizedby a rotation about the axis 48 of rotation illustrated in FIG. 2. Thisrotational movement can be realized, for example, by a rotationalsliding guide as it is known from a ballpoint pen, for example.

The high-pressure cleaning device 1 is configured such that the switchelement 3 can be moved between the first switched state and the secondswitched state due to a force effected by the cleaning liquid or due toa force which is effected by the user. The user can effect selectivelyswitching of the switch element 3 by actuation of the switch actuatingelement 21 or by manual actuation of the switch element 3 withoututilizing the pressure of the cleaning liquid.

In the state of the high-pressure cleaning device 1 illustrated in FIG.5, no cleaning liquid sprays from the spray opening 19. In the elementsection 16 of the conveying conduit 10, there is no or only very littlecleaning liquid at no pressure or very minimal pressure. The drainagereturn channel 30 is blocked by an interrupting element 39. Theinterrupting element 39 prevents a flow of cleaning liquid from thepressure section 25 toward the element section 16. The interruptingelement 39 is a component of the switch actuating element 21. Thehigh-pressure cleaning device 1 is configured such that in the passageposition 22 of the switch actuating element 21 a fluid communicationbetween the holding section 24 and the pressure section 25 of the branchconduit 20 can be produced and, at the same time, the drainage returnchannel 30 can be interrupted in regard to fluid communication such thata flow of cleaning liquid from the pressure section 25 to the elementsection 16 is prevented.

FIGS. 6 and 7 show the high-pressure cleaning device 1 with theconveyance actuating element 11 in the closed position 13 and the switchactuating element 21 in the blocking position 23. In FIG. 6, theactuator 6 is still in its adjusted position 8; in FIG. 7, it hasalready been returned into its rest position 7. In order for theactuator 6 to return into its rest position 7, the holding pressure ofthe cleaning liquid which is present in the pressure section 25 of thebranch conduit 20 must be relieved. The high-pressure cleaning device 1is configured in such a way that, when the switch actuating element 21is in its blocking position 23, the drainage check valve 31 is switchedand connected to the drainage return channel 30 at the same time and, inthis way, the pressure section 25 is connected in the d irection fromthe pressure section 25 toward the element section 16 in fluidcommunication with the element section 16. From the pressure section 25,the cleaning liquid can flow through the drainage return channel 30 intothe element section 16. A flow of cleaning liquid in the direction fromthe element section 16 to the pressure section 25 is prevented by thedrainage check valve 31. This is also illustrated in FIG. 3 in which theconveyance actuating element 11 is in the open position 12 and, at thesame time, the switch actuating element 21 is in the blocking position23.

The high-pressure cleaning device 1 is configured such that the drainagereturn channel 30 in the passage position 22 of the switch actuatingelement 21 is interrupted and, in the blocking position 23 of the switchactuating element 21, a flow of cleaning liquid is enabled only in thedirection from the pressure section 25 to the element section 16. Thehigh-pressure cleaning device 1 is configured such that the drainagecheck valve 31 of the switch actuating element 21 in the blockingposition 23 of the switch actuating element 21 is switched and connectedto the drainage return channel 30. The drainage check valve 31 in theembodiment according to FIGS. 1 through 8 is a component of the switchactuating element 21. The high-pressure cleaning device 1 is configuredsuch that the drainage check valve 31 in the passage position 22 of theswitch actuating element 21, due to the adjustment of the switchactuating element 21 out of the blocking position 23 into the passageposition 22, is removed from the drainage return channel 30. In thepassage position 22 of the switch actuating element 21, due to theadjustment of the switch actuating element 21, the interrupting element39 is switched and connected to the drainage return channel 30 (FIG. 5).The connection between the pressure section 25 and the element section16 is interrupted with respect to fluid communication. When theconveyance actuating element 11 is in the closed position 13, the switchactuating element 21 is in the blocking position 23, and, at the sametime, the actuator 6 is in the adjusted position 8, cleaning liquid canflow from the pressure section 25 through the drainage return channel 30and the drainage check valve 31 to the element section 16 of theconveying conduit 10 (FIG. 6).

As indicated in FIG. 6 by the dotted line, this cleaning liquid is atlow pressure. The low pressure is lower than the high pressure buthigher than the minimal pressure, or hardly existing pressure, of thecleaning liquid. The cleaning liquid which is draining through thedrainage return channel 30 in this way can advance to the spray opening19 and can exit therethrough. This can be done drop by drop. In thisway, the holding pressure in the pressure section 25 is relieved. At thesame time, the pressure in the pressure chamber 32 of the hydrauliccylinder 40 decreases also. The pressure which is generated by the thirdrestoring spring 9 acting on the actuator 6 is then higher than theholding pressure. The third restoring spring 9 can then force theactuator from the adjusted position 8 into the rest position 7. T hishappens upon transition from FIG. 6 to FIG. 7.

In the embodiment according to FIGS. 1 through 8, the high-pressurecleaning device 1 is configured such that the switch actuating element21 can be pushed sequentially as often as desired in order to adjust theswitch element 3. The pressure of the cleaning liquid which is presentin the holding section 24 is always sufficient in order to move theactuator 6 from its rest position 7 into its adjusted position 8. Aftera user has pushed the switch actuating element 21 from the blockingposition 23 into the passage position 22 and has released the switchactuating element 21 again, the switch actuating element 21automatically returns from the passage position 22 into the blockingposition 23. This is realized due to the restoring force of the firstrestoring spring 26.

FIG. 8 shows the high-pressure cleaning device 1 after the switchelement 3 has been adjusted. Instead of the first work element 4, nowthe second work element 5 is in the conveying conduit 10. The switchactuating element 21 is in its blocking position 23, and the conveyanceactuating element 11 is in its open position 12. The conveying pump 2conveys cleaning liquid from the liquid container 36 through theconveying conduit 10 to the spray opening 19. Cleaning liquid is sprayedunder high pressure out of the spray opening 19. With the exception ofthe difference that now the second work element 5 instead of the firstwork element 4 is arranged in the conveying conduit 10, thehigh-pressure cleaning device 1 is in the same state as in FIG. 3. Whenthe switch actuating element 21 is actuated again, a further, differentwork element can be switched and connected to the conveying conduit 10.In the embodiment according to FIGS. 1 through 8, it is provided that,for a total of n working elements, the first work element 4 is switchedand connected again to the conveying conduit 10 after n switchingoperations with the switch actuating element 21. Then the switch element3 has carried out a complete revolution by 360° about the axis ofrotation 48 illustrated in FIG. 2.

The high-pressure cleaning device 1 is configured such that the actuator6 can adjust the switch element 3 also by a force which is exerted bythe user of the high-pressure cleaning device 1 on the actuator 6.

In the embodiment according to FIGS. 1 through 8, the work elements arenozzles. However, it can also be provided that the switch element 3switches and connects other work elements to the conveying lines 10.

For example, by means of the switch element 3 work elements can beswitched into the conveying conduit 10 that enable switching of therotational direction of a hydraulic motor. For this purpose, a workelement comprises a supply line and a return line to a circuit of ahydraulic motor. The circuit is a component of the conveying conduit.The work element divides the element section into a first sectionbetween the conveyance actuating element 11 and the work element andinto a second section between the work element and the spray opening 19.The circuit of the hydraulic motor comprises an inlet and an outlet. Afirst work element connects the first section of the element section 16with the inlet of the circuit and connects the outlet of the circuit tothe second section of the element section 16. A second work elementconnects the first section of the element section 16 to the outlet ofthe circuit and connects the inlet of the circuit to the second sectionof the element section 16. By switching between the first work elementand the second work element, switching of the rotational direction ofthe hydraulic motor arranged in the circuit can be effected.

The switch element 3 can however also be used for switching on and offan additional nozzle. In this manner, for example, a corner nozzle ofthe surface cleaning device can be switched on or off. For this purpose,in the second section of the element section 16 two conduits would haveto be provided. When switching and connecting a first work element tothe conveying conduit 10, both conduits would be flushed; when switchingand connecting a second work element to the conveying conduit 10, onlyone conduit would be flushed. This one conduit could then be the conduitfor the surface cleaner, for example.

A similar configuration can also be utilized for branching off a portionof the volume flow. In this context, it can also be provided to arrangethe work elements at the end of the conveying line 10 at the sprayopening 19 instead of within the conveying conduit 10. Downstream of thework elements, then two conduits can be arranged, and only one or bothcan be flushed depending on the inserted work element. When bothconduits are flushed, a portion of the volume flow can be branched off.From the branch conduit, cleaning liquid can then exit and pressure canbe relieved in this way.

The switch element according to the invention can also be used forswitching between two injector nozzles for admixing different cleaningagents.

The first and the second switched states can also be different gearstages of a gear. In this case, it is not different work elements thatare switched and connected to the conveying conduit, but the switchelement is actuated independent of the conveying conduit. The actuatorcan then change, for example, the position of a gear wheel. By such amechanical engagement in a gear, in a targeted manner transmissionratios can be changed without having to accept disadvantageous losses.Such an action of the actuator on a gear can also be used for switchingthe rotational direction.

The specification incorporates by reference the entire disclosure ofEuropean priority document 20 185 778.6 having a filing date of Jul. 14,2020.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the inventive principles, it will beunderstood that the invention may be embodied otherwise withoutdeparting from such principles.

What is claimed is:
 1. A high-pressure cleaning device comprising: aconveying pump; a conveying conduit comprising a spray opening, theconveying conduit configured to convey cleaning liquid, conveyed by theconveying pump, in a conveying direction from the conveying pump to thespray opening of the conveying conduit; a switch element comprising atleast a first switched state and a second switched state; an actuatorconfigured to adjust the switch element between the first switched stateand the second switched state; the high-pressure cleaning deviceconfigured such that the actuator is configured to adjust the switchelement between the first switched state and the second switched stateby an adjusting force effected by the cleaning liquid on the actuator.2. The high-pressure cleaning device according to claim 1, furthercomprising at least a first work element and a second work element,wherein, in the first switched state of the switch element, the firstwork element is switched and connected to the conveying conduit andwherein, in the second switched state of the switch element, the secondwork element is switched and connected to the conveying conduit.
 3. Thehigh-pressure cleaning device according to claim 2, wherein the firstwork element and the second work element are nozzles.
 4. Thehigh-pressure cleaning device according to claim 1, further comprising aconveyance actuating element comprising an open position and a closedposition, wherein the conveyance actuating element in the open positionpermits the cleaning liquid to pass through the conveying conduit fromthe conveying pump to the spray opening, and wherein the conveyanceactuating element in the closed position prevents the cleaning liquidfrom passing through the conveying conduit from the conveying pump tothe spray opening.
 5. The high-pressure cleaning device according toclaim 4, further comprising a branch conduit that branches off theconveying conduit at a branch location of the conveying conduit andconnects the conveying conduit to the actuator.
 6. The high-pressurecleaning device according to claim 5, further comprising a switchactuating element arranged between the branch location and the actuator,wherein the switch actuating element comprises a passage position and ablocking position, wherein the switch actuating element in the passageposition permits the cleaning liquid to pass through the branch conduit,and wherein the switch actuating element in the blocking positionprevents the cleaning liquid from passing through the branch conduit. 7.The high-pressure cleaning device according to claim 6, wherein thebranch conduit is divided into a holding section extending from thebranch location to the switch actuating element and into a pressuresection extending from the switch actuating element to the actuator,wherein, in operation of the high-pressure cleaning device, a holdingpressure is present in the holding section of the branch conduit whenthe switch actuating element is in the blocking position and theconveyance actuating element is in the closed position.
 8. Thehigh-pressure cleaning device according to claim 7, wherein thehigh-pressure cleaning device is configured such that the holdingpressure is increased by the conveying pump when the switch actuatingelement is in the blocking position and the conveyance actuating elementis in the closed position.
 9. The high-pressure cleaning deviceaccording to claim 7, wherein the holding pressure is at least highenough to provide the adjusting force effected by the cleaning liquid onthe actuator for adjusting the switch element.
 10. The high-pressurecleaning device according to claim 7, wherein the branch location of theconveying conduit is arranged between the conveying pump and theconveyance actuating element.
 11. The high-pressure cleaning deviceaccording to claim 7, further comprising a conveyance check valvearranged in the conveying conduit between the branch location of theconveying conduit and the conveying pump, wherein the conveyance checkvalve is configured to prevent a flow of the cleaning liquid in adirection opposite to the conveying direction.
 12. The high-pressurecleaning device according to claim 7, wherein, in operation of thehigh-pressure cleaning device, when the switch actuating element isswitched from the blocking position into the passage position when theholding pressure in the holding section of the branch conduit is highenough to provide the force for adjusting the switch element, thecleaning liquid advances from the holding section into the pressuresection of the branch conduit and exerts the adjusting force effected bythe cleaning liquid on the actuator for adjusting the switch element.13. The high-pressure cleaning device according to claim 6, furthercomprising a drainage return channel connecting the pressure section ofthe branch conduit to an element section of the conveying conduit,wherein the element section of the conveying conduit extends from theconveyance actuating element to the spray opening, wherein the drainagereturn channel is interrupted in the passage position of the switchactuating element and is open in the blocking position of the switchactuating element to permit a flow of the cleaning liquid only in adirection from the pressure section to the element section.
 14. Thehigh-pressure cleaning device according to claim 13, wherein the switchactuating element comprises a drainage check valve, wherein the drainagecheck valve is switched and connected to the drainage return channel inthe blocking position of the switch actuating element, and wherein thedrainage check valve is removed from the drainage return channel in thepassage position of the switch actuating element.
 15. The high-pressurecleaning device according to claim 6, wherein the switch actuatingelement is operatively connected to a restoring spring such that theswitch actuating element is loaded by the restoring spring in adirection toward the blocking position.
 16. The high-pressure cleaningdevice according to claim 4, wherein the conveyance actuating element isoperatively connected to a restoring spring such that the conveyanceactuating element is loaded by the restoring spring in a directiontoward the closed position.
 17. The high-pressure cleaning deviceaccording to claim 1, wherein the actuator comprises a rest position andan adjusted position, wherein the actuator for adjusting the switchelement is moved from the rest position into the adjusted position andwherein the actuator is operatively connected to a restoring spring suchthat the actuator is loaded by the restoring spring in a directiontoward the rest position
 18. The high-pressure cleaning device accordingto claim 1, wherein the actuator is guided in a cylinder of a hydrauliccylinder.
 19. The high-pressure cleaning device according to claim 1,wherein the actuator is configured to be adjusted by a force effected bya user acting on the actuator for adjusting the switch element.